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  • The EMBO Journal (2004) 23, 2009 - 2017
  • doi:10.1038/sj.emboj.7600200

Published online: 22 April 2004

Type IV pilus retraction in pathogenic Neisseria is regulated by the PilC proteins

Philippe C Morand1,2, Emmanuelle Bille1,a, Sandrine Morelle1,a, Emmanuel Eugène1, Jean-Luc Beretti1, Matthew Wolfgang3, Thomas F Meyer2, Michael Koomey4 and Xavier Nassif1

  1. INSERM U570, Faculté de Médecine Necker-Enfants Malades, Paris, France
  2. Abteilung Molekulare Biologie, Max-Planck-Institut für Infektionsbiologie, Berlin, Germany
  3. Department of Microbiology and Immunology and Cystic Fibrosis, Pulmonary Research and Treatment Center, University of North Carolina, Chapel Hill, NC, USA
  4. Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway

Correspondence to:

Xavier Nassif, INSERM U570, Faculté de Médecine Necker-Enfants Malades, 156, rue de Vaugirard, 75015 Paris, France. Tel.: +33 1 4061 5379; Fax: +33 1 4061 5592; E-mail: nassif@necker.fr

aThese authors contributed equally to this work

Received 7 October 2003; Accepted 10 March 2004

Pathogenic Neisseria express type IV pili (tfp), which have been shown to play a central role in the interactions of bacteria with their environment. The regulation of piliation thus constitutes a central element in bacterial life cycle. The PilC proteins are outer membrane-associated proteins that have a key role in tfp biogenesis since PilC-null mutants appear defective for fibre expression. Moreover, tfp are also subjected to retraction, which is under the control of the PilT nucleotide-binding protein. In this work, we bring evidence that fibre retraction involves the translocation of pilin subunits to the cytoplasmic membrane. Furthermore, by engineering meningococcal strains that harbour inducible pilC genes, and with the use of meningococcus–cell interaction as a model for the sequential observation of fibre expression and retraction, we show that the PilC proteins regulate PilT-mediated fibre retraction.

  • Keywords:

    • pathogenic Neisseria,
    • PilC,
    • PilT,
    • retraction,
    • type IV pili